Put both lists in one place

MANIFEST.in

@@ -1,5 +1,4 @@
 include CHANGES.txt
-include CONTRIBUTORS.txt
 include COPYRIGHT.txt
 include LICENSES.txt
 include README.rst

docs/development.rst

@@ -47,10 +47,11 @@ Contributors
 ~~~~~~~~~~~~
 
 Contributors are tracked on the `GitHub contributions page
-<https://github.com/Supervisor/supervisor/graphs/contributors>`_.
+<https://github.com/Supervisor/supervisor/graphs/contributors>`_.  The two lists
+below are included for historical reasons.
 
-The list below recognizes significant contributions that were made before
-the repository moved to GitHub.
+This first list recognizes significant contributions that were made
+before the repository moved to GitHub.
 
 - Anders Quist: Anders contributed the patch that was the basis for
   Supervisor’s ability to reload parts of its configuration without
@@ -75,3 +76,58 @@ the repository moved to GitHub.
 - Siddhant Goel: Siddhant worked on :program:`supervisorctl` as our
   Google Summer of Code student for 2008. He implemented the ``fg``
   command and also added tab completion.
+
+This second list records contributors who signed a legal agreement.
+The legal agreement was
+`introduced <https://github.com/Supervisor/supervisor/commit/7bdac36e67a91b513a2e53a6098751509a7a9e34>`_
+in January 2014 but later
+`withdrawn <https://github.com/Supervisor/supervisor/commit/79090d521c512634bed03a65147f16cd41456051>`_
+in March 2014.  This list is being preserved in case it is useful
+later (e.g. if at some point there was a desire to donate the project
+to a foundation that required such agreements).
+
+- Chris McDonough, 2006-06-26
+
+- Siddhant Goel, 2008-06-15
+
+- Chris Rossi, 2010-02-02
+
+- Roger Hoover, 2010-08-17
+
+- Benoit Sigoure, 2011-06-21
+
+- John Szakmeister, 2011-09-06
+
+- Gunnlaugur Þór Briem, 2011-11-26
+
+- Jens Rantil, 2011-11-27
+
+- Michael Blume, 2012-01-09
+
+- Philip Zeyliger, 2012-02-21
+
+- Marcelo Vanzin, 2012-05-03
+
+- Martijn Pieters, 2012-06-04
+
+- Marcin Kuźmiński, 2012-06-21
+
+- Jean Jordaan, 2012-06-28
+
+- Perttu Ranta-aho, 2012-09-27
+
+- Chris Streeter, 2013-03-23
+
+- Caio Ariede, 2013-03-25
+
+- David Birdsong, 2013-04-11
+
+- Lukas Rist, 2013-04-18
+
+- Honza Pokorny, 2013-07-23
+
+- Thúlio Costa, 2013-10-31
+
+- Gary M. Josack, 2013-11-12
+
+- Márk Sági-Kazár, 2013-12-16